Can changing flow RTN an acro?

Kongar · Aug 5, 2021

Just had an acro that's been in the tank for about 6 months bleach out 100% overnight. Polyp extension and looked normal the night before - a bone white skeleton the next morning. Man that was fast. What changed? I changed the flow.

I put in a new millie a few weeks ago, and I decided it was getting a bit blasted by my return (showing some stress on the side getting blasted. Figured I'd have this problem with other corals as they grew up, so I pointed my return nozzle differently. Definitely made the flow less turbulent for the acro that poofed, but I would still say it was "high flow"

Did a full round of tests on the water - nothing changed - all good. (premptive what's the numbers? alk8.7, ph 8.0, ca 460, mg 1360, nitrates 2, phosphates 0.06).

Must have been the flow change. Man these things are picky. Hope it's not a bug or disease or something - this is two in the last couple of weeks. A new frag and now an older one. =\

Is changing the flow a big deal? Big enough to nuke a colony overnight? I wouldn't have thought so - but I've made mistakes before...

vetteguy53081 · Aug 5, 2021

If too much yes. More so would be lack of light or both

homer1475 · Aug 5, 2021

Unless you went from normal flow to perhaps blasting it, I can see RTN. But going the other way, I personally have never had an issue with changing flow up.

NowGlazeIT · Aug 5, 2021

Depends on the coral. Some can be so unhappy with the current conditions (but still surviving) that a small change like flow pattern can be the last straw.

Kongar · Aug 5, 2021

It was growing like a weed. Huge extension. I would have said it was the happiest sps in the tank. Apparently not.

Flow went down, not up. Lights are the same. Everybody else is happy (except to be honest a single chalice that’s never been happy - but that’s been a slow decline for over a year.

Frankly I’m shocked. I fear somethings up with my tank and I don’t know what…. Hobby is fun as heck, but it has its share of mysteries (and solving them usually points to yourself as the culprit)